XEMStrategy {blockcluster}R Documentation

An EM strategy to obtain a good optimum.


In Co-clustering, there could be many local optimal where the algorithm may get struck resulting in sub-optimum results. Hence we applied a strategy called XEM strategy to run the EM algorithm. The various steps are defined as follows:


Step-1, "xem" step:

Do several runs of: "initialization followed by short run of algorithm (few iterations/high tolerance)". This parameter is named as "nbxem" in coclusterStrategy function. Default value is 5. We call this step as xem step.

Step-2, "XEM" step:

Select the best result of step 1 and make long run of Algorithm(high iterations/low tolerance).We call this step as XEM step.


Repeat step 1 and 2 several times and select the best result. The number of repetitions can be modified via parameter "nbtry" of coclusterStrategy function. Default value is 2.

[Package blockcluster version 4.5.5 Index]